The Victorian naturalist . nt, within the area of downwarping. Dur-ing the past milHon years these crustalmovements have continued, and in-deed there are still earthquakes in thePort Phillip region, some of whichhave been traced to movements alongfaults. The Mornington earthquake of1932 was due to a displacement alongSelwyn Fault, the alignment of whichpasses from Frankston to McCrae andthence southward through the Nepean Peninsula to emerge on the oceanshore just west of Cape Schanck. During Pleistocene times the sunk-land created by these crustal move-ments became a marine embaymenton the si
The Victorian naturalist . nt, within the area of downwarping. Dur-ing the past milHon years these crustalmovements have continued, and in-deed there are still earthquakes in thePort Phillip region, some of whichhave been traced to movements alongfaults. The Mornington earthquake of1932 was due to a displacement alongSelwyn Fault, the alignment of whichpasses from Frankston to McCrae andthence southward through the Nepean Peninsula to emerge on the oceanshore just west of Cape Schanck. During Pleistocene times the sunk-land created by these crustal move-ments became a marine embaymenton the site of Port Phillip Bay atstages of relatively high sea level,and drained out as a coastal lowlandwhen sea level fell. As the sea with-drew, the ancestral Yarra River ex-tended its course, and was joined by. Plate 2 Dune beddingon the shorenear PearsesBeach. 134 Vic. Nat. Vol. 92 tributaries from the bordering up-lands, and probably from King Islandand northern Tasmania as well, beforeit entered the lowered ocean some-where south of Cape Otway, on thewest coast of an isthmus of land thatextended across what is now BassStrait. When sea level rose again theBassian isthmus was submerged, iso-lating Tasmania from mainland Aus-tralia, and the Port Phillip embaymentwas revived. Its configuration differedat each stage, depending on the levelattained by the rising sea, and onintervening changes due to continuingcrustal deformation and the modifica-tion of the land surface by erosionand deposition processes. Riversgradually carved out valleys andbuilt up flood-plains and deltas; rain-wash smoothed hill slopes; wavestrimmed back the land margin toform cliffs in some sectors, and builtup beaches in others; tidal currentsscoured the floor of the Port Phillipembayment when sea level was high,and winds
Size: 3261px × 767px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdec, booksubjectnaturalhistory, bookyear1884
